Bristle unit used for toothbrush and implanting method thereof

ABSTRACT

A reel-shaped bristle unit  10  comprising a set of strands of bristles  4  formed by bending a plurality of strands  1 , made of synthetic resin filament such as nylon, into two in a U-shape and by aggregating the strands  1  as a bunch, wherein a lead wire for winding  3  common to the center of the strands  2  is fixed by welding or adhering thereto, wherein a spiral groove  7  is formed at a circumference  6  of a bristle reel  8  in which one or more rows of said set of strands of bristles  4  are plunged into the groove  7,    
     Said set of strands of bristles  4  is plunged into the spiral groove  7  in such a manner to be wound spirally around the groove  7  of the waist of the reel  8  with a spiral pitch along it from one end of the lead wire  3  while the center of the strands  2  is fixed by the lead wire  3 , wherein a free end of the set of the stands  4  extends above the reel while a clearance  9  is provided between the grooves  7  adjacent to each other.

TECHNICAL FIELD

The present invention relates to a toothbrush used in oral prophylaxis. In particularly, it relates to a bristle unit provided at the end of a handle, and more specifically to a bristle unit in a reel shape provided so as to rotate freely on an axis.

BACKGROUND ART

A toothbrush used for removing or preventing bacterial plaque and dental calculus, which form on teeth and gums, is the most important and commonly used instrument among dental cleaning tools (refer to non-patent reference 1).

A toothbrush is mainly categorized into a manual toothbrush and an electric toothbrush. A “toothbrush”, in general, refers to a manual toothbrush. This toothbrush consists of a brush head into which bristles made of natural hair or synthetic filaments such as nylon yarn are implanted, a handle, and a neck connecting the head and the handle. Tuft holes into which a number of bristles have been implanted are provided at the brush head. In general, each bristle (hair) is folded in a U-shape in such a manner to be plunged into the tuft holes and to be fixed horizontally so as to be implanted approximately vertically or radially (in a flabelliform). The configuration of the bristle unit (bristle implanted part) when viewed laterally from the side can be roughly classified into three types, that is, a liner type where a brushing plan is parallel to the brush head, a convex curving type, and a concaving type. Furthermore, a tuft type and an inclined type may be seen on the market. The implant condition of the bristle unit can be categorized into non-dense bristles in which the bunches of bristles are spaced apart from each other and dense bristles in which the bunches of bristles are spaced close to each other. For the non-dense bristles, the number of row of the bristle bunches is between one and three and the number of the bristle bunches is between six and 27 while the dense bristles refer to those having four or more rows.

In order to brush the teeth, generally, while holding the handle, the user rubs the bristles across all the surfaces of each tooth side to side, up and down, brushes back and forth with wide strokes or rotation so as to remove bacteria plaques and to massage gums with gentle pressure.

The toothbrush with non-dense bristles tends to repel water and dry easily, which is effective to retain hygiene. On the other hand, a dense bristle brush is considered to be preferable for brushing method using the edge of the brush for cleaning between teeth and gums.

The following are prior art documents relating to various forms of toothbrush.

Other than the aforementioned widely known toothbrush, recent trends focus on newly developed types, a so-called “rotating toothbrush” or a “roll toothbrush,” in which a freely rotatable brush is provided at the end of a handle, or the arrangement of the embedded bristle parts is circular or radial (for example, refer to the following patent documents 1-7).

-   [Non-patent Document 1] “Toothbrush encyclopedia” 3^(rd) edition, Y.     Matsuda and I. Kondo, Gakken-shoin, October, 2002. -   [Patent Document 1] Design Pat. Registration No. 1066543 -   [Patent Document 2] Utility Model publication No. 63-120929 -   [Patent Document 3] Utility Model Registration No. 3104356 -   [Patent Document 4] Patent Unexamined Publication No. 2000-83736 -   [Patent Document 5] Patent Unexamined Publication No. 2003-219911 -   [Patent Document 6] Patent Unexamined Publication No. 2003-220080 -   [Patent Document 7] Patent Unexamined Publication No. 2003-289947

In the toothbrush of the above patent documents 1, 2, and 4-7, a bristle unit of a radial pattern is provided at the end of a handle in a rotatable manner. A bristle unit is produced in such a manner that a number of sets of strands (hair) made of nylon are aggregated as a tuft wherein the sets of strands are fixed to spread wherein the center part of the sets of strands is welded circularly to form a toroidal welded part. A sheet type bristle unit is provided by cutting off the inner periphery of the toroidal welded part circularly to form a circular penetrating hole. After a plurality of the sheet type bristle units have been accumulated, a pipe is inserted into the penetrating hole to make it a roll shape. The roll shape bristle unit is arranged in such a manner to be supported in a rotatable part by a spindle extending on one end of the bristle unit member.

In the toothbrush of the patent document 3, a plurality of bristle units of approximately disc shape are accumulated in such a manner to be centered at the end axis of a handle of a toothbrush so as to make it a roller shape. This roll shape bristle unit is arranged in such a manner to be supported in a rotatable manner by a spindle extending on one end of the handle member.

SUMMARY OF THE INVENTION [Problems Solved by the Invention]

As described before, in a conventional toothbrush, for example, after a plurality of sheet type bristle units have been accumulated, the bristle units are formed in a roller shape by inserting a pipe into the center penetrating hole, which is then supported by a spindle extending on one end side of a handle in a rotatable manner. Or a bristle unit of approximately disc shape is arranged at the end of the handle of a toothbrush in such a manner to be perpendicular to the spindle.

Referring to the implant condition of bristles, in most cases, a bunch of bristles is close to each other. The reason is assumed that due to the production method of roller shaped bristle units, a number of sheet type bristle units are accumulated so closely that they are densely implanted as a whole. Because the bristles are close to each other, it is difficult to apply in a brushing method in which brush ends are used for cleaning between teeth and gums. In addition, it is difficult to drain water and dry the brush. It is also unsanitary because plaques caught among bristles cannot be rinsed off completely.

Furthermore, it is difficult to adjust the interval of this bristle unit arrangement.

[Means for Solving the Problems]

The present invention provides a bristle unit and implanting method thereof that can solve the aforementioned problems.

Namely, the present invention provides a bristle unit for a toothbrush comprising:

a reel having a spiral groove around its circumference;

a plurality of strands made of synthetic resin filament such as nylon;

and a lead wire for winding a strand;

said plurality of strands are bent into two in a U-shape, wherein the lead wire which is common to the center part of the bent strands is fixed by welding or adhering so that the lead wire is plunged into the spiral groove around the reel circumference with the spiral pitch along the groove,

wherein a free end of the strand extends above the reel circumference, and the ejecting edges are trimmed to have a roller shape as a whole.

The brush head comprises an axis member (spindle) supporting the reel. Said axis member is inserted into a penetrating hole provided at the center of the reel waist so as to support the bristle unit in a freely rotatable manner.

The implanting method of the bristles of this invention comprises the combination of the following steps [A] to [C]:

[A] preparing a set of strands of bristles 4 formed by bending a plurality of strands 1, made of synthetic resin filament such as nylon, into two in a U-shape and by aggregating the strands 1 as a bunch, wherein a lead wire for winding 3 common to the center of the strands 2 is fixed by welding or adhering thereto;

[B] preparing a reel for bristles 8 by providing a spiral groove 7 around its circumference 6 so that one or more rows of said set of strands of bristles 4 are plunged into the groove 7; and

[C] plunging said set of strands of bristles 4 into the spiral groove 7 in such a manner to be wound spirally around the groove 7 of the waist of the reel 8 with a spiral pitch along it from one end of the lead wire 3 while the center of the strands 2 is fixed by the lead wire 3, wherein a free end of the set of the stands 4 extends above the reel while a clearance 9 is provided between the strands plunged into the grooves 7 adjacent to each other.

The following effects can be achieved by the present invention:

[i] The accumulation of a set of strands of bristles can be decreased, and therefore, a toothbrush having a low density of bristle implants can be produced; [ii] The set of strands of bristles are plunged into spiral grooves around the circumference of a bristle reel with a predetermined spiral pitch in such a manner to be wound spirally. Thereby, arrangement of a bunch of bristles is adjustable by adjusting the space of the spiral grooves of the reel waist. [iii] Because the rows of bristles are separated from each other, it is easy to drain water and dry the brush, which allows the brush to be kept clean. [iv] The brush edges can reach between teeth easily so that plaques can be removed more effectively. [v] The bristle unit for this toothbrush can be produced without complicated technique, which results in easy mass production of the product.

The present invention will be best understood from the following description of specific embodiment(s) when read in connection with the accompanying drawings. However, it will be understood that the present invention is not limited to those embodiment(s).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of the toothbrush of the present invention.

FIG. 2 is a plan view of FIG. 1.

FIG. 3 is a front view of another embodiment of the toothbrush of the present invention.

FIG. 4 is a side view of FIG. 3.

FIG. 5 is an explanation view of the lead wire for winding.

FIG. 6 is an explanation view of the strand of bristles.

FIG. 7 is an explanation view of the combination of the lead wire and the strand.

FIG. 8 is an explanation view of a set of the strands of bristles.

FIG. 9 is an explanation view of the reel of the present invention.

FIG. 10 is a longitudinal section of the reel.

FIG. 11 is a view illustrating the process of winding a set of the strands of bristles around the reel.

FIG. 12 is a view illustrating the process of winding a set of the strands of bristles around a spiral groove of the reel.

FIG. 13 is a side view of the bristle units.

FIG. 14 is a longitudinal section of the bristle units.

BEST MODE OF CARRYING OUT THE INVENTION

FIG. 1 is a side view of the toothbrush 20 equipped with a freely rotatable bristle unit of a reel shape according to the present invention. FIG. 2 is a plan view of FIG. 1.

As shown in the drawings, one longitudinal end side of a handle 12 is formed wider than the other end side approximately from the middle thereof. A non-skid is formed at a grip denoted by reference numeral 13. A reel shaped bristle unit 10 is interposed between supporting pieces 14, 14 of both sides of a brush head formed at the other end of the handle 12 in such a manner to insert a spindle 11 equipped with a head into a penetrating hole 5 formed at the middle of the waist of the bristle unit 10 through one of the supporting pieces 14. Then, for example, by welding the other end of the spindle 11 to the supporting piece or by press-crushing means, the roll shaped bristle unit 10 is supported through the spindle 11 in a freely rotatable manner at one longitudinal end of the handle 12.

In FIG. 1, a cover partially veiling the peripheral surface of the roll shaped bristle unit 10 is provided at the brush head in the integrated structure. However, this cover is an option and may be eliminated. In other embodiments, for example, shown in FIGS. 3 and 4, the supporting pieces 14 of the brush head may be simply formed in a forked shape.

The handle 12 and the brush head of this toothbrush are formed by using sanitarily harmless synthetic resin. For example, polypropylene or polyester resin may be used to form into approximately 170 to 175 mm width by injection molding.

Next, the bristle unit will be explained.

The bristle unit 10 of the present invention comprises a reel 8 having spiral grooves around its circumference, a plurality of strands 1 made of synthetic resin filament such as nylon, and a lead wire for winding the strands 3:

Said plurality of strands 1 are bent into two in a U-shape so that the lead wire for winding 3 which is common to the bent center part is fixed by welding or adhering thereto while the lead wire 3 is plunged in such a manner to be wound around a spiral groove 7 arranged on the circumference of the reel 8 at a spiral pitch along the spiral groove,

wherein said reel for bristles 8 comprises a circular penetrating hole 5 for a spindle 11 which is supported rotatably at one end of the handle 12 of the toothbrush.

A set of strands of bristles 4 will be described in detail.

A plurality of strands 1 made of synthetic monofilament such as nylon is bent into two in a U-shape to be aggregated into a bunch so that a common lead wire for winding 3 is fixed to the center part 2 of the thus bent strand by welding or adhering so as to form a set of strands of bristles 4 (see FIGS. 5 to 8).

Next, as shown in FIG. 9, a reel is prepared. A spiral groove 7 is formed on the peripheral face of the waist of the reel 6 in such a manner that one or more rows of strands of bristles 4 are pushed therein. By using this bristle reel 8, the set of strands of bristles 4 is wound spirally from one end of the lead wire 3 around a spiral groove around the waist 7 of the reel 8 and plunged into the groove 7 of the bristle reel 8 in such a manner that the center part of the strand 2 is fixed by the lead wire 3. While a free end of the set of strands 4 extends above the reel body, a clearance 9 is provided between the strands plunged into grooves adjacent to each other so as to form a bristle unit for toothbrush 10 in the reel shape (see FIG. 9 to 14).

Similar to the material of the aforementioned handle, the reel 8 may be made of synthetic resin such as polypropylene or polyester resin to have 10 mm in diameter and 20 mm in width and include a spiral groove 7 having 2.5 mm in depth and 1-4 mm in width by, for example, injection molding.

A strand 1 may be made of synthetic monofilament such as polyethylene other than nylon. Such a synthetic monofilament may have a 0.13-0.30 mm diameter and approximately 15 mm in length. Those strands 1 are aggregated into a bunch and fixed in such a manner to be bent in a U-shape and to have the lead wire 3 at their center so as to form a shape with an effective length of 7.5 mm (see FIG. 8).

The further process for forming a bristle unit of the toothbrush includes a step of plunging one end of the lead wire 3 so as to wind spirally with a spiral pitch along a spiral groove 7 around the circumference of a reel 8 while the reel is rotated in such a manner that the center part 2 of the strands of bristles 4 is fixed to the lead wire 3 by welding or adhering (see FIGS. 11 and 12). Next, while a free end of the set of strands 4 extends above the reel for a predetermined length, a clearance 9 of a predetermined width is provided between the grooves 7 adjacent to each other (see FIG. 13) so as to form a bristle unit of the reel shape 10.

After plunging the set of strands 4 into the spiral groove 7, the center of the strand 2 and the spiral groove 7 can be fixed to each other as needed.

Although one row of strands of bristles 4 is plunged into the spiral groove 7 in this embodiment, it will be understood that three or four rows of strands 4 can be plunged into the groove 7 (not shown in the drawings).

Although one reel is used in this embodiment, a plurality of reels with a small width may be connected to each other to form a bristle unit having a predetermined width (not shown in the drawings).

The edges of the set of strands 4 extending above the reel may be trimmed to have a predetermined length using an appropriate edge trimmer. Then, the thus obtained bristle unit 10 is interposed between the support pieces 14, 14 of the brush head arranged at the other end of the handle 12 in such a manner that the spindle 11 through the head penetrates from one support piece to the other support piece through the penetrating hole 5 formed at the center of the bristle unit 10. Thereafter, the reel-shaped bristle unit 10 is rotatably supported by the support pieces 14 through the spindle 11 at one longitudinal end of the handle 12 by compression bonding or welding the other end of the spindle 11 (see FIG. 14).

The toothbrush having the bristle unit 10 obtained through the above process is packaged and shipped after the process of inspection. 

1. A bristle unit to be mounted on a brush head of the top of a handle of a toothbrush comprising: a reel having spiral grooves on its circumference; a plurality of strands made of synthetic resin filament such as nylon; and a lead wire for winding the strands, said plurality of strands are bent into two in a U-shape so that the lead wire for winding which is common to the bent center part is fixed by welding or adhering thereto while the lead wire is plunged in such a manner to be wound around a spiral groove arranged around the circumference of the reel at a spiral pith along the spiral groove, Wherein a free end of the set of strands extended above the circumference of the reel in a predetermined length, wherein the edges of the ejecting part are trimmed so as to form the bristle unit in the reel shape as a whole.
 2. A bristle unit mounted on a brush head of the top of a handle of a toothbrush in a freely rotatable manner, said bristle unit comprising: a reel having spiral grooves on its circumference; a plurality of strands made of synthetic resin filament such as nylon; and a lead wire for winding the strands, said plurality of strands are bent into two in a U-shape so that the lead wire for winding which is common to the bent center part is fixed by welding or adhering thereto while the lead wire is plunged in such a manner to be wound around a spiral groove arranged around the circumference of the reel at a spiral pith along the spiral groove, Wherein a free end of the set of strands extended above the waist of the reel in a predetermined length, wherein the edges of the ejecting part are trimmed so as to form the bristle unit in a reel shape as a whole, said brush head comprises an axis member supporting the reel wherein the axis member is inserted into a penetrating hole provided at the center of the reel body so as to support the bristle unit in a freely rotatable manner.
 3. An implanting method of a bristle unit for a toothbrush comprising the following steps [A] to [C]: [A] preparing a set of strands of bristles formed by bending a plurality of strands, made of synthetic resin filament such as nylon, into two in a U-shape and by aggregating the strands as a bunch, wherein a lead wire for winding common to the center of the strands is fixed by welding or adhering thereto; [B] preparing a reel for bristles by providing a spiral groove on its circumference so that one or more rows of said set of strands of bristles are plunged into the groove; and [C] plunging said set of strands of bristles into the spiral groove in such a manner to be wound spirally around the groove on the circumference of the reel with a spiral pitch along it from one end of the lead wire while the center of the strands is fixed by the lead wire, wherein a free end of the set of the stands extends above the reel while a clearance is provided between the strands plunged into the grooves adjacent to each other. 